U.S. patent application number 14/338295 was filed with the patent office on 2014-11-13 for power converter and method for manufacturing power converter.
This patent application is currently assigned to KABUSHIKI KAISHA YASKAWA DENKI. The applicant listed for this patent is KABUSHIKI KAISHA YASKAWA DENKI. Invention is credited to Tomokazu HONDA, Kiyonori KOGUMA, Yuji NODA, Akira SASAKI, Kunihiro TAKENAKA, Yu UJITA.
Application Number | 20140334203 14/338295 |
Document ID | / |
Family ID | 48904644 |
Filed Date | 2014-11-13 |
United States Patent
Application |
20140334203 |
Kind Code |
A1 |
HONDA; Tomokazu ; et
al. |
November 13, 2014 |
POWER CONVERTER AND METHOD FOR MANUFACTURING POWER CONVERTER
Abstract
A power converter includes a switch element, a snubber
capacitor, and a connection conductor configured to connect the
switch element and the snubber capacitor to each other, and at
least a part of the connection conductor is arranged to be held
between the snubber capacitor and an electrode of the switch
element.
Inventors: |
HONDA; Tomokazu;
(Kitakyushu-shi, JP) ; SASAKI; Akira;
(Kitakyushu-shi, JP) ; KOGUMA; Kiyonori;
(Kitakyushu-shi, JP) ; TAKENAKA; Kunihiro;
(Kitakyushu-shi, JP) ; UJITA; Yu; (Kitakyushu-shi,
JP) ; NODA; Yuji; (Kitakyushu-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KABUSHIKI KAISHA YASKAWA DENKI |
Kitakyushu-shi |
|
JP |
|
|
Assignee: |
KABUSHIKI KAISHA YASKAWA
DENKI
Kitakyushu-shi
JP
|
Family ID: |
48904644 |
Appl. No.: |
14/338295 |
Filed: |
July 22, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2012/052119 |
Jan 31, 2012 |
|
|
|
14338295 |
|
|
|
|
Current U.S.
Class: |
363/56.12 ;
29/825 |
Current CPC
Class: |
H01L 2224/131 20130101;
H01L 2224/73265 20130101; Y02B 70/1491 20130101; Y02B 70/10
20130101; H01L 2924/13091 20130101; Y10T 29/49117 20150115; H01L
24/73 20130101; H01L 25/072 20130101; H02M 2001/346 20130101; H01L
23/642 20130101; H01L 2224/291 20130101; H02M 7/003 20130101; H01L
25/115 20130101; H01L 2224/16245 20130101; H01L 25/16 20130101;
H01L 2224/32245 20130101; H01L 2224/73207 20130101; H01L 2224/48227
20130101; H01L 2924/15321 20130101; H02M 1/34 20130101; H02M 7/537
20130101; H01L 2224/16227 20130101; H01L 2924/13055 20130101; H02M
2001/348 20130101; H01L 2924/1305 20130101; H01L 2224/16225
20130101; H01L 2224/73204 20130101; H01L 2224/73253 20130101; H01L
2924/13055 20130101; H01L 2924/00 20130101; H01L 2224/131 20130101;
H01L 2924/014 20130101; H01L 2224/291 20130101; H01L 2924/014
20130101; H01L 2224/73204 20130101; H01L 2224/16245 20130101; H01L
2224/32245 20130101; H01L 2924/00 20130101; H01L 2924/1305
20130101; H01L 2924/00 20130101 |
Class at
Publication: |
363/56.12 ;
29/825 |
International
Class: |
H02M 1/34 20060101
H02M001/34; H02M 7/537 20060101 H02M007/537 |
Claims
1. A power converter comprising: a switch element having an
electrode; a snubber capacitor connected to the electrode of the
switch element; and a connection conductor configured to connect
the electrode of the switch element and the snubber capacitor to
each other, wherein at least a part of the connection conductor is
arranged to be held between the snubber capacitor and the electrode
of the switch element.
2. The power converter according to claim 1, wherein the switch
element includes a first switch element having a front surface side
electrode arranged on a side of the connection conductor and a
second switch element having a rear surface side electrode arranged
on the side of the connection conductor, and at least the part of
the connection conductor is arranged to be held between the snubber
capacitor and the front surface side electrode of the first switch
element or between the snubber capacitor and the rear surface side
electrode of the second switch element.
3. The power converter according to claim 2, wherein the connection
conductor includes a first connection conductor configured to
connect the snubber capacitor and the front surface side electrode
of the first switch element to each other and a second connection
conductor configured to connect the snubber capacitor and the rear
surface side electrode of the second switch element to each
other.
4. The power converter according to claim 2, further comprising a
first substrate mounted with the first switch element and the
second switch element, wherein a first conductive pattern
configured to connect a rear surface side electrode of the first
switch element and a front surface side electrode of the second
switch element to each other is provided on a front surface of the
first substrate.
5. The power converter according to claim 1, wherein the connection
conductor is bonded to the snubber capacitor through a bonding
material.
6. The power converter according to claim 1, wherein the connection
conductor is employed in common for a plurality of the snubber
capacitors.
7. The power converter according to claim 6, wherein a three-phase
inverter circuit is configured by connecting three half-bridge
circuits each including the switch element to the plurality of
snubber capacitors in parallel to each other, and the connection
conductor is arranged across the switch element of each of the
three half-bridge circuits and the plurality of snubber capacitors
in common.
8. The power converter according to claim 1, further comprising a
heat radiating member arranged on a side of the snubber capacitor
opposite to a side connected with the connection conductor.
9. The power converter according to claim 1, further comprising a
first substrate mounted with the switch element on a front surface,
wherein a region between the front surface of the first substrate
and the connection conductor is filled with a sealing resin.
10. The power converter according to claim 1, wherein the
connection conductor is made of a plate-like conductor, the snubber
capacitor is connected to a front surface of the connection
conductor made of the plate-like conductor, and the electrode of
the switch element is connected to a rear surface of the connection
conductor made of the plate-like conductor.
11. The power converter according to claim 1, further comprising a
first substrate mounted with the switch element on a front surface,
wherein at least one conductive pattern electrically connected to
the switch element, constituting a terminal is provided on a rear
surface of the first substrate.
12. The power converter according to claim 11, wherein the
electrode of the switch element includes: a first electrode
provided on a front surface side, electrically connected to the
snubber capacitor, and a second electrode for control provided on a
rear surface side, electrically connected to an external portion,
the first substrate includes a second conductive pattern provided
on the front surface and a third conductive pattern electrically
connected to the second conductive pattern, provided on the rear
surface, the second conductive pattern of the first substrate is
connected to the second electrode for control provided on the rear
surface side of the switch element, and the third conductive
pattern of the first substrate constitutes a first control terminal
connected to an external portion.
13. The power converter according to claim 12, wherein the first
substrate includes a fourth conductive pattern provided on the
front surface and a fifth conductive pattern electrically connected
to the fourth conductive pattern, provided on the rear surface in
addition to the second conductive pattern and the third conductive
pattern, the fourth conductive pattern of the first substrate is
connected to the connection conductor arranged to be held between
the snubber capacitor and the electrode of the switch element, and
the fifth conductive pattern of the first substrate constitutes a
terminal.
14. The power converter according to claim 1, further comprising a
second substrate configured to include the connection conductor,
wherein the second substrate includes a sixth conductive pattern
provided on a front surface and a seventh conductive pattern
electrically connected to the sixth conductive pattern, provided on
a rear surface, the seventh conductive pattern of the second
substrate is connected to the electrode of the switch element, and
the sixth conductive pattern of the second substrate is connected
to the snubber capacitor.
15. The power converter according to claim 14, wherein the
electrode of the switch element includes a first electrode
electrically connected to the snubber capacitor and a second
electrode for control electrically connected to an external
portion, the second substrate further includes an eighth conductive
pattern provided on the front surface and a ninth conductive
pattern electrically connected to the eighth conductive pattern,
provided on the rear surface in addition to the sixth conductive
pattern and the seventh conductive pattern, the seventh conductive
pattern of the second substrate is connected to the first electrode
of the switch element, the ninth conductive pattern of the second
substrate is connected to the second electrode for control of the
switch element, and the eighth conductive pattern of the second
substrate constitutes a second control terminal connected to an
external portion.
16. The power converter according to claim 14, wherein the sixth
conductive pattern of the second substrate constitutes a
terminal.
17. The power converter according to claim 14, further comprising a
first substrate mounted with the switch element, wherein the first
substrate is arranged such that a front surface of the first
substrate is opposed to the rear surface of the second substrate
and includes a recess portion configured to mount the switch
element and a protruding portion adjacent to the recess portion,
and the protruding portion of the first substrate is bonded to the
rear surface of the second substrate.
18. The power converter according to claim 1, wherein the switch
element includes a power conversion semiconductor element, and at
least the part of the connection conductor is arranged to be held
between the snubber capacitor and the electrode of the power
conversion semiconductor element.
19. A method for manufacturing a power converter comprising a
switch element having an electrode and a snubber capacitor,
comprising: connecting the electrode of the switch element to a
rear surface side of a connection conductor; and connecting the
snubber capacitor to a front surface side of the connection
conductor such that at least a part of the connection conductor is
held between the snubber capacitor and the electrode of the switch
element.
20. The method for manufacturing a power converter according to
claim 19, wherein the switch element includes a first switch
element having a front surface side electrode arranged on a side of
the connection conductor and a second switch element having a rear
surface side electrode arranged on the side of the connection
conductor, the method for manufacturing a power converter further
comprising bonding a rear surface side of the first switch element
to a front surface of a first substrate, wherein connecting the
electrode of the switch element includes: bonding a rear surface
side of the second switch element to a rear surface of a second
substrate including the connection conductor to connect the rear
surface side electrode of the second switch element to the rear
surface side of the connection conductor of the second substrate,
and bonding the front surface of the first substrate to which the
rear surface side of the first switch element is bonded and the
rear surface of the second substrate to which the rear surface side
of the second switch element is bonded to each other in a state
where the front surface of the first substrate and the rear surface
of the second substrate are opposed to each other to connect the
front surface side electrode of the first switch element to the
rear surface side of the connection conductor of the second
substrate.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of PCT/JP2012/052119,
Power Converter and Method for Manufacturing Power Converter, Jan.
31, 2012, Tomokazu Honda, Akira Sasaki, Kiyonori Koguma, Kunihiro
Takenaka, Yu Ujita, and Yuji Noda.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a power converter and a
method for manufacturing a power converter.
[0004] 2. Description of the Related Art
[0005] In general, a power converter including a switch element and
a snubber capacitor is known. Such a power converter is disclosed
in Japanese Patent Laying-Open No. 2011-067045, for example.
[0006] In the aforementioned Japanese Patent Laying-Open No.
2011-067045, there is disclosed an inverter device (power
converter) including a MOSFET (switch element) having an electrode
and a snubber capacitor. This inverter device is provided with a
metal substrate having an upper surface on which the MOSFET is
arranged and a dielectric substrate having a lower surface on which
the snubber capacitor is arranged, and the upper surface of the
metal substrate and the lower surface of the dielectric substrate
are opposed to each other. On the upper surface of the metal
substrate and the lower surface of the dielectric substrate, wiring
patterns are provided. The wiring patterns provided on the upper
surface of the metal substrate and the lower surface of the
dielectric substrate are electrically connected to the electrode of
the MOSFET and the snubber capacitor. This inverter device is
provided with a plate-like wiring portion (connection conductor)
configured to electrically connect the wiring pattern provided on
the upper surface of the metal substrate and the wiring pattern
provided on the lower surface of the dielectric substrate to each
other. Thus, the snubber capacitor and the MOSFET are electrically
connected to each other through three wiring portions (conductors)
of the wiring pattern provided on the upper surface of the metal
substrate, the plate-like wiring portion, and the wiring pattern
provided on the lower surface of the dielectric substrate.
SUMMARY OF THE INVENTION
[0007] A power converter according to a first aspect includes a
switch element having an electrode, a snubber capacitor connected
to the electrode of the switch element, and a connection conductor
configured to connect the electrode of the switch element and the
snubber capacitor to each other, and at least a part of the
connection conductor is arranged to be held between the snubber
capacitor and the electrode of the switch element.
[0008] A method for manufacturing a power converter according to a
second aspect is a method for manufacturing a power converter
including a switch element having an electrode and a snubber
capacitor and includes steps of connecting the electrode of the
switch element to the rear surface side of a connection conductor
and connecting the snubber capacitor to the front surface side of
the connection conductor such that at least a part of the
connection conductor is held between the snubber capacitor and the
electrode of the switch element.
[0009] The wiring inductance between the snubber capacitor and the
switch element can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a circuit diagram of a three-phase inverter device
including a power module according to a first embodiment;
[0011] FIG. 2 is a diagram of the power module according to the
first embodiment as viewed from the side;
[0012] FIG. 3 is a diagram of the power module shown in FIG. 2 as
viewed from above;
[0013] FIG. 4 is a diagram of a substrate of the power module shown
in FIG. 2 as viewed from below;
[0014] FIG. 5 is a diagram of the substrate shown in FIG. 4 as
viewed from above;
[0015] FIG. 6 is a diagram of the upper surface of the substrate
shown in FIG. 5 mounted with a first switch element and a second
switch element as viewed from above;
[0016] FIG. 7 is a diagram showing a state where connection
conductors are arranged on the front surface side of the first
switch element and the rear surface side of the second switch
element shown in FIG. 6 as viewed from above;
[0017] FIG. 8 is a diagram of a power module according to a second
embodiment as viewed from the side;
[0018] FIG. 9 is a diagram of the power module shown in FIG. 8 as
viewed from above;
[0019] FIG. 10 is a diagram of a first substrate of the power
module shown in FIG. 9 as viewed from below;
[0020] FIG. 11 is a diagram of the first substrate shown in FIG. 10
as viewed from above;
[0021] FIG. 12 is a diagram of the upper surface of the first
substrate shown in FIGS. 10 and 11 mounted with a first switch
element as viewed from the side;
[0022] FIG. 13 is a diagram of a second substrate of the power
module shown in FIG. 9 as viewed from above;
[0023] FIG. 14 is a diagram of the second substrate shown in FIG.
13 as viewed from below;
[0024] FIG. 15 is a diagram of the lower surface of the second
substrate shown in FIGS. 13 and 14 mounted with a second switch
element as viewed from the side;
[0025] FIG. 16 is a diagram for illustrating a process for bonding
the first substrate shown in FIG. 12 and the second substrate shown
in FIG. 13 to each other;
[0026] FIG. 17 is a diagram of a power module according to a third
embodiment as viewed from the side;
[0027] FIG. 18 is a diagram of the power module shown in FIG. 17 as
viewed from above;
[0028] FIG. 19 is a diagram of a power module according to a fourth
embodiment as viewed from above;
[0029] FIG. 20 is a diagram of the power module shown in FIG. 19 as
viewed from the side;
[0030] FIG. 21 is a diagram of a power module according to a
modification of the first embodiment as viewed from above;
[0031] FIG. 22 is a diagram of a power module according to a
modification of the second embodiment as viewed from above; and
[0032] FIG. 23 is a diagram of a power module according to a
modification of the third embodiment as viewed from the side.
DESCRIPTION OF THE EMBODIMENTS
[0033] Embodiments are hereinafter described on the basis of the
drawings.
First Embodiment
[0034] The structure of a three-phase inverter device 100 including
power modules 100a, 100b, and 100c according to a first embodiment
is now described with reference to FIG. 1. The power modules 100a
to 100c are examples of the "power converter". The three-phase
inverter device 100 is an example of the "power converter" or the
"three-phase inverter circuit".
[0035] As shown in FIG. 1, the three power modules 100a, 100b, and
100c performing U-phase, V-phase, and W-phase power conversion,
respectively, are electrically connected in parallel to each other,
whereby the three-phase inverter device 100 is configured. These
three power modules 100a to 100c are provided as separate devices
and are connected to each other by unshown wires or the like formed
of metal wires.
[0036] The power modules 100a, 100b, and 100c include half-bridge
circuits 101a, 101b, and 101c configured to perform U-phase,
V-phase, and W-phase power conversion, respectively and snubber
capacitors 10a, 10b, and 10c electrically connected in parallel to
the half-bridge circuits 101a, 101b, and 101c, respectively. Each
of the half-bridge circuits 101a, 101b, and 101c is configured to
include two switch elements (a first switch element 11a and a
second switch element 12a, a first switch element 11b and a second
switch element 12b, or a first switch element 11c and a second
switch element 12c) electrically connected in series with each
other. The first switch elements 11a, 11b, and 11c and the second
switch elements 12a, 12b, and 12c are examples of the "power
conversion semiconductor element".
[0037] Each of the first switch elements 11a, 11b, and 11c is
constituted by a MOSFET (field-effect transistor) having three
electrodes (a gate electrode G1a, G1b, or G1c, a source electrode
S1a, S1b, or S1c, and a drain electrode D1a, D1b, or D1c). Each of
the second switch elements 12a, 12b, and 12c is also constituted by
a MOSFET having three electrodes (a gate electrode G2a, G2b, or
G2c, a source electrode S2a, S2b, or S2c, and a drain electrode
D2a, D2b, or D2c).
[0038] The first switch elements 11a, 11b, and 11c and the second
switch elements 12a, 12b, and 12c are configured to perform
switching on the basis of control signals externally input through
control terminals 51a, 51b, and 51c and control terminals 52a, 52b,
and 52c, respectively, to convert direct-current power input
through input terminals 53 and 54 into three-phase (U-phase,
V-phase, and W-phase) alternating-current power. Furthermore, the
first switch elements 11a, 11b, and 11c and the second switch
elements 12a, 12b, and 12c are configured to output the
alternating-current power obtained by the aforementioned conversion
to an external portion through output terminals 55a, 55b, and 55c.
The input terminals 53 and 54 are connected to a P-electrode (+V)
and an N-electrode (-V) of an unshown direct-current power supply,
respectively. The output terminals 55a, 55b, and 55c are connected
to respective unshown motors or the like.
[0039] The detailed structure of the power modules 100a, 100b, and
100c according to the first embodiment is now described with
reference to FIGS. 2 and 3. The power modules 100a, 100b, and 100c
have substantially the same structure, and hence only the power
module 100a including the two switch elements (the first switch
element 11a and the second switch element 12a) and the snubber
capacitor 10a is described below.
[0040] As shown in FIGS. 2 and 3, the power module 100a includes a
substrate 1, the two switch elements (the first switch element 11a
and the second switch element 12a), two connection conductors 31
and 32, and the snubber capacitor 10a. The substrate 1 is an
example of the "first substrate". The connection conductors 31 and
32 are examples of the "first connection conductor" and the "second
connection conductor", respectively.
[0041] The substrate 1 is configured to include an insulating plate
2 and ten conductive patterns 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i,
and 3j provided on the front surface (upper surface: surface along
an arrow Z2) and the rear surface (lower surface: surface along
arrow Z1) of the insulating plate 2. The insulating plate 2 is made
of an insulator such as ceramic in the form of a flat plate. The
conductive patterns 3a to 3j each are made of a conductor of
copper, gold, silver, aluminum, or alloy containing those in the
form of a flat plate.
[0042] The conductive patterns 3a, 3c, 3e, 3g, and 3i and the
conductive patterns 3b, 3d, 3f, 3h, and 3j are electrically
connected to each other through columnar conductors 3k, 3l, 3m, 3n,
and 3o provided to pass through the insulating plate 2 from the
upper surface (the surface along arrow Z2) to the lower surface
(the surface along arrow Z1), respectively. The conductive pattern
3e is an example of the "first conductive pattern". The conductive
pattern 3c is an example of the "second conductive pattern", and
the conductive pattern 3d is an example of the "third conductive
pattern". The conductive patterns 3a and 3i are examples of the
"fourth conductive pattern", and the conductive patterns 3b and 3j
are examples of the "fifth conductive pattern". The conductive
patterns 3a, 3c, 3e, 3g, and 3i and the conductive patterns 3b, 3d,
3f, 3h, and 3j, respectively, may be electrically connected to each
other through hollow conductors like through vias, not the columnar
conductors 3k, 3l, 3m, 3n, and 3o.
[0043] The first switch element 11a and the second switch element
12a are aligned in a direction X on the front surface (upper
surface: surface along arrow Z2) of the substrate 1. In the
following description, a surface provided with the drain electrode
D1a (D2a) of the first switch element 11a (second switch element
12a) is set to the front surface of the first switch element 11a
(second switch element 12a), and a surface provided with the gate
electrode G1a (G2a) and the source electrode S1a (S2a) of the first
switch element 11a (second switch element 12a) is set to the rear
surface of the first switch element 11a (second switch element
12a).
[0044] According to the first embodiment, the first switch element
11a and the second switch element 12a are arranged such that the
front surfaces and the rear surfaces thereof are oppositely
oriented to each other, as shown in FIG. 2. Specifically, whereas
the drain electrode D1a provided on the front surface side of the
first switch element 11a is arranged on the rear surface (lower
surface: surface along arrow Z1) side of the connection conductor
31, the drain electrode D2a provided on the front surface side of
the second switch element 12a is arranged on the front surface
(upper surface: surface along arrow Z2) side of the substrate 1.
Whereas the gate electrode G1a and the source electrode S1a
provided on the rear surface side of the first switch element 11a
are arranged on the upper surface aside of the substrate 1, the
gate electrode G2a and the source electrode S2a provided on the
rear surface side of the second switch element 12a are arranged on
the lower surface side of the connection conductor 32.
[0045] The drain electrode D1a of the first switch element 11a is
bonded to the lower surface (surface along arrow Z1) of the
connection conductor 31 through a bonding layer 41 made of solder
or the like. The source electrode S1a and the gate electrode G1a of
the first switch element 11a are bonded to the upper surfaces
(surfaces along arrow Z2) of the conductive patterns 3c and 3e of
the substrate 1 through a plurality of bumps 42. The drain
electrode D2a of the second switch element 12a is bonded to the
upper surface of the conductive pattern 3c of the substrate 1
through a bonding layer 43. The source electrode S2a of the second
switch element 12a is bonded to the lower surface of the connection
conductor 32 through a plurality of bumps 44. The gate electrode
G2a of the second switch element 12a is electrically connected to
the upper surface of the conductive pattern 3g of the substrate 1
through a wire 20 formed of a metal wire or the like. The source
electrode S1a (gate electrode G1a) of the first switch element 11a
and the conductive pattern 3c (3e) may be bonded to each other
through a bonding layer made of solder or a bonding material other
than solder, a plate-like conductor, or the like, not the bumps 42.
Furthermore, the source electrode S1a (gate electrode G1a) of the
first switch element 11a and the conductive pattern 3c (3e) may be
bonded to each other only in a part of a region where the source
electrode S1a (gate electrode G1a) of the first switch element 11a
and the conductive pattern 3c (3e) are opposed to each other or may
be bonded to each other in all of the region where the source
electrode S1a (gate electrode G1a) of the first switch element 11a
and the conductive pattern 3c (3e) are opposed to each other. Much
the same is true on bonding between the source electrode S2a of the
second switch element 12a and the connection conductor 32.
[0046] As hereinabove described, the connection conductors 31 and
32 are arranged above (on sides along arrow Z2 of) the first switch
element 11a and the second switch element 12a, respectively. The
connection conductors 31 and 32 each are made of a conductor of
copper, gold, silver, aluminum, or alloy containing those in the
form of a flat plate. The snubber capacitor 10a is arranged across
the upper surfaces (surfaces along arrow Z2) of the two connection
conductors 31 and 32. Specifically, one electrode C1a and the other
electrode C2a of the snubber capacitor 10a are bonded to the upper
surfaces of the connection conductors 31 and 32, respectively,
through bonding materials 60 made of conductive adhesives such as
solder or conductive paste (silver paste, for example). Thus, the
connection conductors 31 and 32 are arranged to be held between the
first switch element 11a and the snubber capacitor 10a and between
the second switch element 12a and the snubber capacitor 10a,
respectively.
[0047] The upper surface (surface along arrow Z2) of the connection
conductor 31 and the upper surface of the conductive pattern 3a of
the substrate 1 are electrically connected to each other through a
wire 20. The upper surface of the connection conductor 32 and the
upper surface of the conductive pattern 3i of the substrate 1 are
electrically connected to each other through a wire 20. A region
between the upper surface of the substrate 1 and the lower surfaces
(surfaces along arrow Z1) of the connection conductors 31 and 32
and a region between the upper surface of the substrate 1 and the
lower surface of the snubber capacitor 10a are filled with a
sealing resin 70 made of an epoxy resin, a silicone resin, or the
like.
[0048] Due to the aforementioned structure, according to the first
embodiment, the conductive pattern 3b provided on the lower surface
(surface along arrow Z1) side of the substrate 1 is electrically
connected to the drain electrode D1a of the first switch element
11a through the columnar conductor 3k, the conductive pattern 3a,
the wire 20, the connection conductor 31, and the bonding layer 41.
Therefore, the conductive pattern 3b constitutes the input terminal
53 (see FIG. 1) connected to the P-electrode (+V) of the unshown
direct-current power supply. The conductive pattern 3d is
electrically connected to the gate electrode G1a of the first
switch element 11a through the columnar conductor 31, the
conductive pattern 3c, and the bumps 42. Therefore, the conductive
pattern 3d constitutes the control terminal 51a (see FIG. 1) into
which the control signal for switching the first switch element 11a
is input. The control terminal 51a is an example of the "first
control terminal".
[0049] Furthermore, the conductive pattern 3f provided on the lower
surface (surface along arrow Z1) side of the substrate 1 is
electrically connected to the source electrode S1a of the first
switch element 11a through the columnar conductor 3m, the
conductive pattern 3e, and the bumps 42 and is electrically
connected to the drain electrode D2a of the second switch element
12a through the columnar conductor 3m, the conductive pattern 3e,
and the bonding layer 43. Therefore, the conductive pattern 3f
constitutes the output terminal 55a (see FIG. 1) connected to the
unshown motor or the like.
[0050] In addition, the conductive pattern 3h provided on the lower
surface (surface along arrow Z1) side of the substrate 1 is
electrically connected to the gate electrode G2a of the second
switch element 12a through the columnar conductor 3n, the
conductive pattern 3g, and the wire 20. Therefore, the conductive
pattern 3h constitutes the control terminal 52a (see FIG. 1) into
which the control signal for switching the second switch element
12a is input. The conductive pattern 3j is electrically connected
to the source electrode S2a of the second switch element 12a
through the columnar conductor 3o, the conductive pattern 3i, the
wire 20, the connection conductor 32, and the bumps 44. Therefore,
the conductive pattern 3j constitutes the input terminal 54 (see
FIG. 1) connected to the N-electrode (-V) of the unshown
direct-current power supply.
[0051] A manufacturing process for the power module 100a according
to the first embodiment is now described with reference to FIGS. 2
to 7.
[0052] First, the substrate 1 provided with the ten conductive
patterns 3a to 3j on the upper surface side (along arrow Z2) and
lower surface side (along arrow Z1) of the insulating plate 2 is
prepared, as shown in FIGS. 4 and 5. Then, the upper surfaces
(surfaces along arrow Z2) of the conductive patterns 3c and 3e of
the substrate 1 and the gate electrode G1a and the source electrode
S1a on the rear surface side of the first switch element 11a,
respectively, are bonded to each other through the bumps 42 made of
solder or the like, and the upper surface of the conductive pattern
3e and the drain electrode D2a on the front surface side of the
second switch element 12a are bonded to each other through the
bonding layer 43 made of solder or the like, as shown in FIGS. 2
and 6.
[0053] Then, the connection conductors 31 and 32 in the form of a
flat plate are arranged on the front surface side of the first
switch element 11a and the rear surface side of the second switch
element 12a, respectively, as shown in FIGS. 2 and 7. Specifically,
the drain electrode D1a on the front surface side of the first
switch element 11a and the lower surface (surface along arrow Z1)
of the connection conductor 31 are bonded to each other through the
bonding layer 41, and the source electrode S2a and the gate
electrode G2a on the rear surface side of the second switch element
12a and the lower surface of the connection conductor 31 are bonded
to each other through the bumps 44. Then, the snubber capacitor 10a
is bonded through the bonding materials 60 across the upper
surfaces (surfaces along arrow Z2) of the connection conductors 31
and 32, as shown in FIGS. 2 and 3.
[0054] At this time, the region between the upper surface (surface
along arrow Z2) of the substrate 1 and the lower surfaces (surfaces
along arrow Z1) of the connection conductors 31 and 32 and the
region between the upper surface of the substrate 1 and the lower
surface of the snubber capacitor 10a are filled with the sealing
resin 70. The upper surfaces of the connection conductors 31 and 32
and the upper surfaces of the conductive patterns 3a and 3i of the
substrate 1, respectively, are electrically connected to each other
through the wires 20.
[0055] In the aforementioned bonding process employing the bonding
layers 41 and 43, the bumps 42 and 44, and the bonding materials 60
made of solder or the like, a solder resist is preferably applied
to prescribed areas (see portions shown by diagonal lines in FIGS.
5 to 7, for example) in order to suppress spread of solder to
unnecessary portions.
[0056] According to the first embodiment, as hereinabove described,
the connection conductor 31 (32) is arranged to be held between the
snubber capacitor 10a and the first switch element 11a (second
switch element 12a). Thus, the snubber capacitor 10a and the first
switch element 11a (second switch element 12a) are electrically
connected to each other through the single conductor (connection
conductor 31 (32)), and hence a conduction path between the snubber
capacitor 10a and the first switch element 11a (second switch
element 12a) can be reduced in length. Consequently, a wiring
inductance between the snubber capacitor 10a and the first switch
element 11a (second switch element 12a) can be reduced.
[0057] According to the first embodiment, as hereinabove described,
the drain electrode D1a on the front surface side of the first
switch element 11a is arranged on the side of the connection
conductor 31, and the source electrode S2a on the rear surface side
of the second switch element 12a is arranged on the side of the
connection conductor 32. Thus, the snubber capacitor 10a and the
drain electrode D1a on the front surface side of the first switch
element 11a can be easily electrically connected to each other
through the connection conductor 31, and the snubber capacitor 10a
and the source electrode S2a on the rear surface side of the second
switch element 12a can be easily electrically connected to each
other through the connection conductor 32.
[0058] According to the first embodiment, as hereinabove described,
the conductive pattern 3e configured to connect the source
electrode S1a on the rear surface side of the first switch element
11a and the drain electrode D2a on the front surface side of the
second switch element 12a to each other is provided on the upper
surface (surface along arrow Z2) of the substrate 1 on which the
first switch element 11a and the second switch element 12a are
arranged. Thus, the source electrode S1a on the rear surface side
of the first switch element 11a and the drain electrode D2a on the
front surface side of the second switch element 12a can be easily
electrically connected to each other through the conductive pattern
3e of the substrate 1.
[0059] According to the first embodiment, as hereinabove described,
the connection conductors 31 and 32 are bonded to the snubber
capacitor 10a through the bonding materials 60. Thus, the
connection conductors 31 and 32 can be strongly bonded to the
snubber capacitor 10a by the bonding materials 60.
[0060] According to the first embodiment, as hereinabove described,
the region between the upper surface (surface along arrow Z2) of
the substrate 1 and the lower surfaces (surfaces along arrow Z1) of
the connection conductors 31 and 32 is filled with the sealing
resin 70. Thus, the entry of extraneous material between the upper
surface of the substrate 1 and the lower surfaces of the connection
conductors 31 and 32 can be suppressed by the sealing resin 70, and
the reliability of insulation can be improved.
[0061] According to the first embodiment, as hereinabove described,
the connection conductors 31 and 32 are made of the conductor in
the form of a flat plate. Furthermore, one electrode C1a and the
other electrode C2a of the snubber capacitor 10a are connected to
the upper surfaces (surfaces along arrow Z2) of the connection
conductors 31 and 32, respectively, and the drain electrode D1a of
the first switch element 11a and the source electrode S2a of the
second switch element 12a are connected to the lower surfaces
(surfaces along arrow Z1) of the connection conductors 31 and 32,
respectively. Thus, the snubber capacitor 10a and the first switch
element 11a and the second switch element 12a are bonded to the
connection conductors 31 and 32 in the form of a flat plate,
whereby bonding areas (plane areas) between the snubber capacitor
10a and the connection conductors 31 and 32 can be increased while
bonding areas (plane areas) between the first switch element 11a
and the connection conductor 31 and between the second switch
element 12a and the connection conductor 32 can be increased.
Consequently, bonding strength between the snubber capacitor 10a
and the connection conductors 31 and 32 can be increased, and
bonding strength between the first switch element 11a and the
connection conductor 31 and between the second switch element 12a
and the connection conductor 32 can be increased.
[0062] According to the first embodiment, as hereinabove described,
the conductive patterns 3d and 3h, the conductive patterns 3b and
3j, and the conductive pattern 3f constituting the control
terminals 51a and 52a, the input terminals 53 and 54, and the
output terminal 55a, respectively, are provided on the lower
surface (surface along arrow Z1) of the substrate 1. Thus, the
control terminals 51a and 52a, the input terminals 53 and 54, and
the output terminal 55a can be easily connected to external devices
(the unshown direct-current power supply, the unshown motor, etc.),
utilizing a region on the lower surface side of the substrate
1.
[0063] According to the first embodiment, as hereinabove described,
the conductive pattern 3c is provided on the upper surface (surface
along arrow Z2) of the substrate 1, and the conductive pattern 3d
electrically connected to the conductive pattern 3c is provided on
the lower surface (surface along arrow Z1) of the substrate 1.
Furthermore, the conductive pattern 3c on the upper surface of the
substrate 1 and the gate electrode G1a provided on the rear surface
side of the first switch element 11a are connected to each other,
and the conductive pattern 3d on the lower surface of the substrate
1 constitutes the control terminal 51a. Thus, the gate electrode
G1a of the first switch element 11a and the control terminal 51a
can be easily connected to each other, unlike the case where the
gate electrode G1a of the first switch element 11a and the control
terminal 51a into which the control signal is externally input are
connected to each other by a wire or the like.
Second Embodiment
[0064] A power module 200a according to a second embodiment is now
described with reference to FIGS. 8 to 16. In this second
embodiment, an example of arranging two switch elements (a first
switch element 11a and a second switch element 12a) in a region
(space) between two substrates (a first substrate 201 and a second
substrate 205) arranged to be opposed to each other is described
unlike the aforementioned first embodiment (see FIG. 2) in which
the two switch elements (the first switch element 11a and the
second switch element 12a) are arranged on the upper surface
(surface along arrow Z2) of the single substrate 1. The power
module 200a is an example of the "power converter".
[0065] First, the structure of the power module 200a according to
the second embodiment is described with reference to FIGS. 8 to 15.
This power module 200a performs U-phase power conversion in a
three-phase inverter device. In other words, also according to the
second embodiment, two power modules (power modules performing
V-phase and W-phase power conversion) having substantially the same
structure as the power module 200a are provided separately from the
power module 200a, similarly to the aforementioned first
embodiment. Only the power module 200a performing U-phase power
conversion is described below for simplification.
[0066] As shown in FIG. 8, the power module 200a includes the first
substrate 201, the two switch elements (the first switch element
11a and the second switch element 12a), the second substrate 205,
and a snubber capacitor 10a.
[0067] As shown in FIGS. 8 and 10 to 12, the first substrate 201 is
configured to include an insulating plate 202 in the form of a flat
plate, conductive patterns 203a, 203b, and 203c provided on the
upper surface (surface along arrow Z2) and lower surface (surface
along arrow Z1) of the insulating plate 202, two insulating plates
204 provided to protrude from the upper surfaces of the conductive
patterns 203a and 203b, and conductive patterns 203d and 203e
provided on the upper surfaces of the two insulating plates 204.
The insulating plates 202 and 204 each are made of an insulator
such as ceramic. The conductive patterns 203a to 203e each are made
of a conductor of copper, gold, silver, aluminum, or alloy
containing those in the form of a flat plate.
[0068] The conductive pattern 203a and the conductive pattern 203d
are electrically connected to each other through a columnar
conductor 203f provided to pass through the insulating plate 204.
Furthermore, the conductive pattern 203b and the conductive pattern
203e are electrically connected to each other through a columnar
conductor 203g provided to pass through the insulating plate 204.
The conductive pattern 203b is an example of the "first conductive
pattern".
[0069] According to the second embodiment, the two insulating
plates 204 arranged in the vicinity of both ends of the first
substrate 201 in a direction X constitute two protruding portions
204a protruding upward (along arrow Z2) from the upper surface
(surface along arrow Z2) of the first substrate 201, as shown in
FIGS. 8 and 12. A space formed by the inner surfaces of these two
protruding portions 204a and the upper surface of the insulating
plate 202 constitutes a recess portion 204b.
[0070] As shown in FIG. 8, the second substrate 205 is arranged
above (on a side along arrow Z2 of) the first substrate 201.
Specifically, the lower surface (surface along arrow Z1) of the
second substrate 205 is bonded to the upper surfaces of the
conductive patterns 203d and 203e provided on the upper surfaces
(surfaces along arrow Z2) of the two insulating plates 204
(protruding portions 204a) through bonding layers 45 made of solder
or the like.
[0071] As shown in FIGS. 8 and 13 to 15, the second substrate 205
is configured to include an insulating plate 206 in the form of a
flat plate and conductive patterns 207a, 207b, 207c, 207d, 207e,
207f, 207g, 207h, 207i, and 207j provided on the upper surface
(surface along arrow Z2) and lower surface (surface along arrow Z1)
of the insulating plate 206. The insulating plate 206 is made of an
insulator such as ceramic. The conductive patterns 207a to 207i
each are made of a conductor of copper, gold, silver, aluminum, or
alloy containing those in the form of a flat plate.
[0072] The conductive patterns 207a, 207c, 207e, 207g, and 207i and
the conductive patterns 207b, 207d, 207f, 207h, and 207j are
electrically connected to each other through columnar conductors
207k, 2071, 207m, 207n, and 207o provided to pass through the
insulating plate 206 from the upper surface (the surface along
arrow Z2) to the lower surface (the surface along arrow Z1),
respectively. The conductive patterns 207c and 207e are examples of
the "sixth conductive pattern", and the conductive patterns 207d
and 207f are examples of the "seventh conductive pattern". The
conductive pattern 207g is an example of the "eighth conductive
pattern", and the conductive pattern 207h is an example of the
"ninth conductive pattern".
[0073] As shown in FIG. 8, the first switch element 11a and the
second switch element 12a having the same structure as those
according to the aforementioned first embodiment are aligned in the
direction X in a region between the upper surface (surface along
arrow Z2) of the first substrate 201 and the lower surface (surface
along arrow Z1) of the second substrate 205 (a space in the
aforementioned recess portion 204b formed by the inner surfaces of
the insulating plates 204 and the conductive patterns 203d and 203e
and the upper surface of the first substrate 201). Also according
to this second embodiment, the first switch element 11a and the
second switch element 12a are arranged such that the front surfaces
and the rear surfaces thereof are oppositely oriented to each
other, similarly to the aforementioned first embodiment.
[0074] In other words, a drain electrode D1a provided on the front
surface side of the first switch element 11a is bonded to the lower
surface (surface along arrow Z1) of the conductive pattern 207d of
the second substrate 205 through a bonding layer 41 made of solder
or the like. A source electrode S1a and a gate electrode G1a
provided on the rear surface side of the first switch element 11a
are bonded to the upper surfaces (surfaces along arrow Z2) of the
conductive patterns 203a and 203b of the first substrate 201,
respectively, through bumps 42 made of solder or the like.
[0075] A drain electrode D2a provided on the front surface side of
the second switch element 12a is bonded to the upper surface
(surface along arrow Z2) of the conductive pattern 203b of the
first substrate 201 through a bonding layer 43. A source electrode
S2a and a gate electrode G1a provided on the rear surface side of
the second switch element 12a are bonded to the lower surfaces
(surfaces along arrow Z1) of the conductive patterns 207f and 207h
of the second substrate 205 through bumps 44, respectively.
[0076] As hereinabove described, the conductive patterns 207d and
207f of the second substrate 205 are arranged above (on sides along
arrow Z2 of) the first switch element 11a and the second switch
element 12a, respectively. As shown in FIGS. 8 and 9, the snubber
capacitor 10a is arranged across the upper surfaces (surfaces along
arrow Z2) of the conductive patterns 207c and 207e of the second
substrate 205. Specifically, one electrode C1a and the other
electrode C2a of the snubber capacitor 10a are bonded to the upper
surfaces of the conductive patterns 207c and 207e of the second
substrate 205, respectively, through bonding materials 60 made of
conductive adhesives such as solder or conductive paste (silver
paste, for example). Thus, the conductive patterns 207c and 207d
and the columnar conductor 207l between the conductive patterns
207c and 207d are arranged to be held between the first switch
element 11a and one electrode C1a of the snubber capacitor 10a.
Similarly, the conductive patterns 207e and 207f and the columnar
conductor 207m between the conductive patterns 207e and 207f are
arranged to be held between the second switch element 12a and the
other electrode C2a of the snubber capacitor 10a. The conductive
patterns 207c and 207d and the columnar conductor 207l are examples
of the "first connection conductor". The conductive patterns 207e
and 207f and the columnar conductor 207m are examples of the
"second connection conductor".
[0077] Also according to this second embodiment, a space between
the upper surface (surface along arrow Z2) of the first substrate
201 and the lower surface (surface along arrow Z1) of the second
substrate 205 is filled with a sealing resin 70, similarly to the
aforementioned first embodiment.
[0078] Due to the aforementioned structure, according to the second
embodiment, the conductive pattern 207a provided on the upper
surface (surface along arrow Z2) side of the second substrate 205
is electrically connected to the gate electrode G1a of the first
switch element 11a through the columnar conductor 207k, the
conductive pattern 207b, the bonding layer 45, the conductive
pattern 203d of the first substrate 201, the columnar conductor
203f, the conductive pattern 203a, and the bump 42. Therefore, the
conductive pattern 207a constitutes a control terminal 51a (see
FIG. 1) into which a control signal for switching the first switch
element 11a is input.
[0079] The conductive pattern 207c provided on the upper surface
(surface along arrow Z2) side of the second substrate 205 is
electrically connected to the drain electrode D1a of the first
switch element 11a through the columnar conductor 207l, the
conductive pattern 207d, and the bonding layer 41. Therefore, the
conductive pattern 207c constitutes an input terminal 53 (see FIG.
1) connected to a P-electrode (+V) of an unshown direct-current
power supply. Furthermore, the conductive pattern 207e of the
second substrate 205 is electrically connected to the source
electrode S2a of the second switch element 12a through the columnar
conductor 207m, the conductive pattern 207f, and the bumps 44.
Therefore, the conductive pattern 207e constitutes an input
terminal 54 (see FIG. 1) connected to an N-electrode (-V) of the
unshown direct-current power supply.
[0080] The conductive pattern 207g provided on the upper surface
(surface along arrow Z2) side of the second substrate 205 is
connected to the gate electrode G2a of the second switch element
12a through the columnar conductor 207n, the conductive pattern
207h, and the bump 44. Therefore, the conductive pattern 207g
constitutes a control terminal 52a (see FIG. 1) into which a
control signal for switching the second switch element 12a is
input. Furthermore, the conductive pattern 207i of the second
substrate 205 is electrically connected to the source electrode S1a
of the first switch element 11a and the drain electrode D2a of the
second switch element 12a through the columnar conductor 207o, the
conductive pattern 207j, the bonding layer 45, the conductive
pattern 203e of the first substrate 201, the columnar conductor
203g, the conductive pattern 203b, and the bonding layer 43.
Therefore, the conductive pattern 207i constitutes a U-phase output
terminal 55a (see FIG. 1) connected to an unshown motor or the
like.
[0081] Next, a manufacturing process for the power module 200a
according to the second embodiment is described with reference to
FIGS. 8 to 16.
[0082] First, the substrate 201 provided with the conductive
patterns 203a to 203c, the two insulating plates 204, and the two
conductive patterns 203d and 203e on the upper surface side (along
arrow Z2) and lower surface side (along arrow Z1) of the insulating
plate 202 is prepared, as shown in FIGS. 10 and 11. Then, the upper
surfaces (surfaces along arrow Z2) of the conductive patterns 203a
and 203b of the first substrate 201 and the gate electrode G1a and
the source electrode S1a on the rear surface side of the first
switch element 11a, respectively, are bonded to each other through
the bumps 42 made of solder or the like, as shown in FIG. 12.
[0083] Then, the second substrate 205 provided with the ten
conductive patterns 207a to 207j on the upper surface side (along
arrow Z2) and lower surface side (along arrow Z1) of the insulating
plate 206 is prepared, as shown in FIGS. 13 and 14. Then, the lower
surfaces (surfaces along arrow Z1) of the conductive patterns 207f
and 207h of the second substrate 205 and the source electrode S2a
and the gate electrode G1a on the rear surface side of the second
switch element 12a, respectively, are bonded to each other through
the bumps 44, as shown in FIG. 15.
[0084] Then, the upper surface (surface along arrow Z2) of the
first substrate 201 bonded with the first switch element 11a and
the lower surface (surface along arrow Z1) of the second substrate
205 bonded with the second switch element 12a are bonded to each
other in a state where the same are opposed to each other, as shown
in FIG. 16. Specifically, the upper surfaces of the conductive
patterns 203d and 203e provided on the upper surfaces of the
insulating plates 204 (protruding portions 204a) protruding upward
(along arrow Z2) from the upper surface of the first substrate 201
in the vicinity of both ends of the first substrate 201 in the
direction X and the lower surfaces of the conductive patterns 207b
and 207j provided on the lower surface of the second substrate 205
in the vicinity of both ends of the second substrate 205 in the
direction X, respectively, are bonded to each other through the
bonding layers 45 made of solder or the like.
[0085] At this time, the drain electrode D1a of the first switch
element 11a bonded to the upper surface (surface along arrow Z2) of
the first substrate 201 and the lower surface (surface along arrow
Z1) of the conductive pattern 207d of the second substrate 205 are
bonded to each other through the bonding layer 41 made of solder or
the like. Furthermore, the drain electrode D2a of the second switch
element 12a mounted on the lower surface of the second substrate
205 and the upper surface of the conductive pattern 203b of the
first substrate 201 are bonded to each other through the bonding
layer 43.
[0086] At this time, the space between the upper surface (surface
along arrow Z2) of the first substrate 201 and the lower surface
(surface along arrow Z1) of the second substrate 205 is filled with
the sealing resin 70, as shown in FIG. 8. Furthermore, the snubber
capacitor 10a is bonded to the upper surfaces of the conductive
patterns 207c and 207e of the second substrate 205 through the
bonding materials 60.
[0087] In the aforementioned bonding process employing the bonding
layers 41, 43, and 45, the bumps 42 and 44, and the bonding
materials 60 made of solder or the like, a solder resist is
preferably applied to prescribed areas (see portions shown by
diagonal lines in FIGS. 11, 13, and 14, for example) in order to
suppress spread of solder to unnecessary portions. Furthermore, in
the aforementioned process for bonding the first substrate 201 and
the second substrate 205 to each other through the bonding layers
45, high temperature solder can be employed for the bumps 42 (44)
and low temperature solder can be employed for the bonding layers
45 in order to suppress melting of the bumps 42 (44) for bonding
the first substrate 201 (second substrate 205) and the first switch
element 11a (second switch element 12a) to each other.
[0088] According to the second embodiment, as hereinabove
described, the conductive patterns 207c and 207e are provided on
the upper surface (surface along arrow Z2) of the second substrate
205, and the conductive patterns 207d and 207f electrically
connected to the conductive patterns 207c and 207e, respectively,
are provided on the lower surface (surface along arrow Z1) of the
second substrate 205. Furthermore, the upper surfaces of the
conductive patterns 207c and 207e are connected to one electrode
C1a and the other electrode C2a of the snubber capacitor 10a,
respectively, and the lower surfaces of the conductive patterns
207d and 207f are connected to the drain electrode D1a of the first
switch element 11a and the source electrode S2a of the second
switch element 12a, respectively. Thus, conduction paths between
the drain electrode D1a of the first switch element 11a and one
electrode C1a of the snubber capacitor 10a and between the source
electrode S2a of the second switch element 12a and the other
electrode C2a of the snubber capacitor 10a can be easily reduced in
length with the second substrate 205 including the conductive
patterns 207c to 207f.
[0089] According to the second embodiment, as hereinabove
described, the conductive pattern 207g is provided on the upper
surface (surface along arrow Z2) side of the second substrate 205,
and the conductive pattern 207h electrically connected to the
conductive pattern 207g is provided on the lower surface (surface
along arrow Z1) side of the second substrate 205. Furthermore, the
conductive pattern 207h and the gate electrode G1a on the rear
surface side of the second switch element 12a are connected to each
other, and the conductive pattern 207g constitutes the control
terminal 52a. Thus, the gate electrode G1a of the second switch
element 12a and the control terminal 52a can be easily connected to
each other, unlike the case where the gate electrode G1a of the
second switch element 12a and the control terminal 52a into which
the control signal is externally input are connected to each other
by a wire or the like.
[0090] According to the second embodiment, the conductive patterns
207c and 207e provided on the upper surface (surface along arrow
Z2) side of the second substrate 205 connected to the snubber
capacitor 10a constitute the input terminals 53 and 54. Thus, the
input terminals 53 and 54 can be easily connected to the unshown
direct-current power supply, utilizing a region on the upper
surface side of the second substrate 205.
[0091] According to the second embodiment, as hereinabove
described, the recess portion 204b configured to arrange the first
switch element 11a and the second switch element 12a and the
protruding portions 204a (insulating plates 204) adjacent to the
recess portion 204b are provided on the upper surface (surface
along arrow Z2) side of the first substrate 201 arranged to be
opposed to the lower surface (surface along arrow Z1) of the second
substrate 205. Furthermore, the conductive patterns 203d and 203e
provided on the protruding portions 204a (insulating plates 204) of
the first substrate 201 and the lower surfaces of the conductive
patterns 207b and 207j of the second substrate 205, respectively,
are bonded to each other. Thus, the first switch element 11a and
the second switch element 12a can be easily arranged between the
upper surface of the first substrate 201 and the lower surface of
the second substrate 205, utilizing the space constituted by the
recess portion 204b of the first substrate 201. In addition, the
protruding portions 204a provided in the first substrate 201 can
stably support the second substrate 205 from below.
Third Embodiment
[0092] The structure of a power module 300a according to a third
embodiment is now described with reference to FIGS. 17 and 18. In
this third embodiment, an example of providing heat radiating
plates 81 and 82 having a heat radiating function on the upper
surface side of a snubber capacitor 10a is described unlike the
aforementioned first embodiment in which nothing is provided on the
upper surface side (side along arrow Z2) of the snubber capacitor
10a. The power module 300a is an example of the "power converter".
The heat radiating plates 81 and 82 are examples of the "heat
radiating member".
[0093] The power module 300a according to the third embodiment
performs U-phase power conversion in a three-phase inverter device.
In other words, also according to this third embodiment, two power
modules (power modules performing V-phase and W-phase power
conversion) having substantially the same structure as the power
module 300a are provided separately from the power module 300a,
similarly to the aforementioned first embodiment. Only the power
module 300a performing U-phase power conversion is described below
for simplification.
[0094] As shown in FIGS. 17 and 18, the power module 300a includes
a substrate 1, two switch elements (a first switch element 11a and
a second switch element 12a), two connection conductors 31 and 32,
the snubber capacitor 10a, and the two heat radiating plates 81 and
82. The heat radiating plates 81 and 82 each are made of a
conductor of metal such as copper excellent in thermal conductivity
in the form of a flat plate.
[0095] According to the third embodiment, the heat radiating plates
81 and 82 are arranged on the upper surface side (side along arrow
Z2) of the snubber capacitor 10a in correspondence to the
connection conductors 31 and 32 arranged to be held between the
snubber capacitor 10a and the first switch element 11a and between
the snubber capacitor 10a and the second switch element 12a,
respectively. Specifically, the lower surface (surface along arrow
Z1) of the heat radiating plate 81 and the upper surface (surface
along arrow Z2) of one electrode C1a of the snubber capacitor 10a
are bonded to each other through a bonding material 61 made of a
conductive adhesive such as solder or conductive paste (silver
paste, for example). Furthermore, the lower surface of the heat
radiating plate 82 and the upper surface of the other electrode C2a
of the snubber capacitor 10a are bonded to each other through a
bonding material 61.
[0096] The remaining structure of the third embodiment is similar
to that of the aforementioned first embodiment.
[0097] According to the third embodiment, as hereinabove described,
the heat radiating plates 81 and 82 are provided on the side (side
along arrow Z2) of the snubber capacitor 10a opposite to the
connection conductors 31 and 32. Thus, the heat radiating plates 81
and 82 can easily radiate heat generated from the snubber capacitor
10a.
Fourth Embodiment
[0098] The structure of a power module 400 according to a fourth
embodiment is now described with reference to FIGS. 19 and 20. In
this fourth embodiment, an example of performing all of U-phase
power conversion, V-phase power conversion, and W-phase power
conversion by a single device (power module (three-phase inverter
device) 400) is described unlike the aforementioned first
embodiment in which U-phase, V-phase, and W-phase power conversion
is performed by the three devices (power modules 100a to 100c)
provided separately from each other. The power module 400 is an
example of the "power converter".
[0099] As shown in FIGS. 19 and 20, the power module 400 includes a
substrate 401, six switch elements (first switch elements 11a to
11c and second switch elements 12a to 12c), two connection
conductors 431 and 432, and three snubber capacitors 10a to 10c.
The substrate 401 is an example of the "first substrate".
[0100] The substrate 401 is configured to include an insulating
plate 402 in the form of a flat plate, nine conductive patterns
(three conductive patterns 403a, three conductive patterns 403c,
and three conductive patterns 403e) provided on the upper surface
(surface along arrow Z2) of the insulating plate 402, and nine
conductive patterns (three conductive patterns 403b, three
conductive patterns 403d, and three conductive patterns 403f)
provided on the lower surface (surface along arrow Z1) of the
insulating plate 402. The conductive patterns 403a, 403c, and 403e
and the conductive patterns 403b, 403d, and 403f are electrically
connected to each other through columnar conductors 403g, 403h, and
403i provided to pass through the insulting plate 402 from the
upper surface to the lower surface, respectively. The three
conductive patterns 403c are examples of the "first conductive
pattern". The three conductive patterns 403a are examples of the
"second conductive pattern", and the three conductive patterns 403b
are examples of the "third conductive pattern".
[0101] As shown in FIGS. 19 and 20, the two switch elements (the
first switch element 11a and the second switch element 12a)
configured to perform U-phase power conversion are aligned in a
direction X on the upper surfaces of the conductive patterns 403a
and 403c provided in the vicinity of an end along arrow Y1 (see
FIG. 19) of the upper surface (surface along arrow Z2) of the
substrate 401. These two switch elements (the first switch element
11a and the second switch element 12a) are arranged such that the
front surfaces and the rear surfaces thereof are oppositely
oriented to each other, similarly to the aforementioned first
embodiment. In other words, a gate electrode G1a on the rear
surface side of the first switch element 11a is bonded to the upper
surface of the conductive pattern 403a of the substrate 401 through
a bump 42. A source electrode S1a on the rear surface side of the
first switch element 11a and a drain electrode D2a on the front
surface side of the second switch element 12a are bonded to the
upper surface of the conductive pattern 403c of the substrate 401
through bumps 42 and a bonding layer 43, respectively.
[0102] Similarly, the first switch element 11b (11c) and the second
switch element 12b (12c) configured to perform V-phase (W-phase)
power conversion are aligned in the direction X on the upper
surfaces of the conductive patterns 403a and 403c provided in the
vicinity of a central portion in a direction Y (in the vicinity of
an end along arrow Y2) (see FIG. 19) of the upper surface (surface
along arrow Z2) of the substrate 401. The first switch element 11b
(11c) and the second switch element 12b (12c) are arranged such
that the front surfaces and the rear surfaces thereof are
oppositely oriented to each other. In other words, a gate electrode
G1b (G1c) on the rear surface side of the first switch element 11b
(11c) is bonded to the upper surface of the conductive pattern 403a
of the substrate 401 through a bump 42. A source electrode S1b
(S1c) on the rear surface side of the first switch element 11b
(11c) and a drain electrode D2b (D2c) on the front surface side of
the second switch element 12b (12c) are bonded to the upper surface
of the conductive pattern 403c of the substrate 401 through bumps
42 and a bonding layer 43, respectively.
[0103] According to the fourth embodiment, the connection
conductors 431 and 432 each are made of a conductor in the form of
a flat plate extending in the direction Y, as shown in FIG. 19.
Thus, the connection conductors 431 and 432 are arranged across the
three first switch elements 11a to 11c and the three second switch
elements 12a to 12c in common, respectively. In other words,
respective drain electrodes D1a to D1c of the three first switch
elements 11a to 11c are bonded to the lower surface (surface along
arrow Z1) of the connection conductor 431 through bonding layers
41, as shown in FIG. 20. Respective source electrodes S2a to S2c on
the rear surface sides of the three second switch elements 12a to
12c are bonded to the lower surface of the connection conductor 432
through bumps 44.
[0104] According to the fourth embodiment, the connection
conductors 431 and 432 are also arranged across the three snubber
capacitors 10a to 10c in common in addition to the aforementioned
six switch elements (the three first switch elements 11a to 11c and
the three second switch elements 12a to 12c). The snubber
capacitors 10a, 10b, and 10c are arranged across the upper surfaces
(surfaces along arrow Z2) of the two connection conductors 431 and
432 in correspondence to the first switch element 11a and the
second switch element 12a, the first switch element 11b and the
second switch element 12b, and the first switch element 11c and the
second switch element 12c, respectively. The snubber capacitors 10a
to 10c are bonded to the upper surfaces of the connection
conductors 431 and 432 through bonding materials 60.
[0105] As hereinabove described, according to the fourth
embodiment, the connection conductors 431 and 432 are arranged to
be held between the three first switch elements 11a to 11c and the
three snubber capacitors 10a to 10c and between the three second
switch elements 12a to 12c and the three snubber capacitors 10a to
10c. The connection conductors 431 and 432 are examples of the
"first connection conductor" and the "second connection conductor",
respectively.
[0106] Also according to this fourth embodiment, a region between
the upper surface (surface along arrow Z2) of the substrate 401 and
the lower surfaces (surfaces along arrow Z1) of the connection
conductors 431 and 432 and a region between the upper surface of
the substrate 401 and the lower surfaces of the snubber capacitors
10a to 10c are filled with sealing resins 70, similarly to the
aforementioned first embodiment. Gate electrodes G1a to G2c of the
second switch elements 12a to 12c are electrically connected to the
respective upper surfaces of the three conductive patterns 403e of
the substrate 401 through wires 20.
[0107] Due to the aforementioned structure, according to the fourth
embodiment, the three respective conductive patterns 403b provided
on the lower surface (surface along arrow Z1) side of the substrate
401 are electrically connected to the gate electrodes G1a to G1c of
the first switch elements 11a to 11c through the columnar
conductors 403g, the conductive patterns 403a, and the bumps 42, as
shown in FIG. 20. Therefore, the three conductive patterns 403b
constitute three control terminals 51a to 51c (see FIG. 1) into
which control signals for switching the first switch elements 11a
to 11c are input.
[0108] The three respective conductive patterns 403d provided on
the lower surface (surface along arrow Z1) side of the substrate
401 are electrically connected to the source electrodes S1a to S1c
of the first switch elements 11a to 11c through the columnar
conductors 403h, the conductive patterns 403c, and the bumps 42 and
are electrically connected to the drain electrodes D2a to D2c of
the second switch elements 12a to 12c through the columnar
conductors 403h, the conductive patterns 403c, and the bonding
layers 43. Therefore, the three respective conductive patterns 403d
constitute U-phase, V-phase, and W-phase output terminals 55a to
55c (see FIG. 1) connected to unshown motors or the like.
[0109] The three respective conductive patterns 403f provided on
the lower surface (surface along arrow Z1) side of the substrate
401 are electrically connected to the gate electrodes G1a to G2c of
the second switch elements 12a to 12c through the columnar
conductors 403i, the conductive patterns 403e and the wires 20.
Therefore, the three respective conductive patterns 403f constitute
three control terminals 52a to 52c (see FIG. 1) into which control
signals for switching the second switch elements 12a to 12c are
input.
[0110] The connection conductor 431 is electrically connected to
the drain electrodes D1a to D1c of the first switch elements 11a to
11c through the bonding layers 41, and the connection conductor 432
is electrically connected to the source electrodes S2a to S2c of
the second switch elements 12a to 12c through the bumps 44.
Therefore, the connection conductors 431 and 432 constitute an
input terminal 53 (see FIG. 1) connected to a P-electrode (+V) of
an unshown direct-current power supply and an input terminal 54
(see FIG. 1) connected to an N-electrode (-V) thereof,
respectively.
[0111] According to the fourth embodiment, as hereinabove
described, the single power module (three-phase inverter device)
400 is configured by connecting the three first switch elements 11a
to 11c and the three second switch elements 12a to 12c to the three
snubber capacitors 10a to 10c in parallel to each other. Thus, the
number of components can be reduced unlike the case where a total
of three power modules of a power module constituted by the first
switch element 11a, the second switch element 12a, and the snubber
capacitor 10a, a power module constituted by the first switch
element 11b, the second switch element 12b, and the snubber
capacitor 10b, and a power module constituted by the first switch
element 11c, the second switch element 12c, and the snubber
capacitor 10c are provided separately from each other (the case
where the three-phase inverter device 100 (see FIG. 1) is
constituted by the three power modules 100a to 100c provided
separately from each other, as in the aforementioned first
embodiment, for example), and hence the structure of the device can
be simplified.
[0112] According to the fourth embodiment, the connection
conductors 431 and 432 are arranged across the three first switch
elements 11a to 11c, the three second switch elements 12a to 12c,
and the three snubber capacitors 10a to 10c in common. Thus, the
number of components can be reduced unlike the case where three
respective connection conductors are provided separately for the
first switch element 11a, the second switch element 12a, and the
snubber capacitor 10a, for the first switch element 11b, the second
switch element 12b, and the snubber capacitor 10b, and for the
first switch element 11c, the second switch element 12c, and the
snubber capacitor 10c, and hence the structure of the device can be
simplified.
[0113] It should be understood by those skilled in the art that
various modifications, combinations, sub-combinations, and
alterations may occur depending on design requirements and other
factors insofar as they are within the scope of the appended claims
or the equivalents thereof.
[0114] For example, while the example of applying the present
invention to the three-phase inverter device (power converter)
including the switch elements and the snubber capacitors has been
shown in each of the aforementioned first to fourth embodiments,
the present invention is also applicable to a power converter other
than the three-phase inverter device, so far as the same includes
switch elements and snubber capacitors.
[0115] While the single snubber capacitor is provided in the single
power module (power converter) in each of the aforementioned first
and second embodiments, two or more snubber capacitors may be
provided in the single power module. As in a modification of the
first embodiment shown in FIG. 21 (a modification of the second
embodiment shown in FIG. 22), for example, two snubber capacitors
10d and 10e (10f and 10g) may be provided in a single power module
110a (210a). The power module 110a (210a) is an example of the
"power converter".
[0116] According to the modification of the first embodiment shown
in FIG. 21, the two snubber capacitors 10d and 10e are provided in
the single power module 110a. These two snubber capacitors 10d and
10e are aligned in a direction Y across the upper surfaces
(surfaces along arrow Z2) of two connection conductors 31 and 32.
Also according to this modification shown in FIG. 21, the
connection conductors 31 and 32 are arranged to be held between a
first switch element 11a and the snubber capacitors 10d and 10e and
between a second switch element 12a and the snubber capacitors 10d
and 10e, respectively, similarly to the aforementioned first
embodiment shown in FIG. 2.
[0117] Similarly, according to the modification of the second
embodiment shown in FIG. 22, the two snubber capacitors 10f and 10g
are provided in the single power module 210a. These two snubber
capacitors 10f and 10g are aligned in a direction Y across the
upper surfaces (surfaces along arrow Z2) of two conductive patterns
207c and 207e provided on the upper surface (surface along arrow
Z2) side of a second substrate 205. Also according to this
modification shown in FIG. 22, conductive patterns 207c and 207d of
the second substrate 205 and a columnar conductor 207l are arranged
to be held between a first switch element 11a and the snubber
capacitors 10f and 10g, similarly to the aforementioned second
embodiment shown in FIG. 8. Furthermore, conductive patterns 207e
and 207f of the second substrate 205 and a columnar conductor 207m
are arranged to be held between a second switch element 12a and the
snubber capacitors 10f and 10g.
[0118] According to the modification of the first embodiment shown
in FIG. 21 (the modification of the second embodiment shown in FIG.
22), as hereinabove described, the single power module 110a (210a)
is provided with the two snubber capacitors 10d and 10e (10f and
10g), whereby more surge voltage can be absorbed, as compared with
the case where the single power module is provided with a single
snubber capacitor (the case of the aforementioned first or second
embodiment).
[0119] While the example of employing the conductive patterns 3b
and 3j provided on the lower surface (surface along arrow Z1) side
of the substrate 1 as the input terminal 53 (see FIG. 1) connected
to the P-electrode (+V) of the unshown direct-current power supply
and the input terminal 54 (see FIG. 1) connected to the N-electrode
(-V) thereof, respectively, has been shown in the aforementioned
third embodiment, as shown in FIG. 17, heat radiating plates 581
and 582 may be employed as the input terminals 53 and 54 (see FIG.
1), respectively, as in a modification of the third embodiment
shown in FIG. 23. The heat radiating plates 581 and 582 are
examples of the "heat radiating member".
[0120] According to the modification of the third embodiment shown
in FIG. 23, the heat radiating plates 581 and 582 each are made of
a conductor of metal such as copper excellent in thermal
conductivity in the form of a flat plate, similarly to the
aforementioned third embodiment. The heat radiating plate 581 is
electrically connected to a drain electrode D1a of a first switch
element 11a through a bonding material 61, one electrode C1a of a
snubber capacitor 10a, a bonding material 60, a connection
conductor 31, and a bonding layer 41. Thus, the heat radiating
plate 581 constitutes an input terminal 53 (see FIG. 1) connected
to a P-electrode (+V) of an unshown direct-current power supply.
The heat radiating plate 582 is electrically connected to a source
electrode S2a of a second switch element 12a through a bonding
material 61, the other electrode C2a of the snubber capacitor 10a,
a bonding material 60, a connection conductor 32, and bumps 44.
Thus, the heat radiating plate 582 constitutes an input terminal 54
(see FIG. 1) connected to an N-electrode (-V) of the unshown
direct-current power supply.
[0121] According to the modification of the third embodiment shown
in FIG. 23, as hereinabove described, the heat radiating plates 581
and 582 are employed as the input terminals 53 and 54 (see FIG. 1),
whereby conductive patterns (the aforementioned conductive patterns
3b and 3j according to the third embodiment shown in FIG. 17)
dedicated for constituting the input terminals 53 and 54 may not be
provided in a substrate 1a, and hence the structure of the device
can be simplified.
[0122] While the example of making each of the heat radiating
plates of a conductor of metal such as copper excellent in thermal
conductivity in the form of a flat plate has been shown in the
aforementioned third embodiment, the heat radiating member may be
made of a member other than metal, so far as the member is
excellent in thermal conductivity.
[0123] While the MOSFET (field-effect transistor) is employed as
each of the switch elements (power conversion semiconductor
elements) in each of the aforementioned first to fourth
embodiments, another transistor such as an IGBT (insulated gate
bipolar transistor) may be employed as each of the switch
elements.
* * * * *